ripping background from snes magical quest 3

hi every one

there's a level in the snes game "magical quest 3 starring mikey and donald"

"Stage 5: Shell Ocean" where a special effect is applied.

the level has been ripped and available in vgmaps but with the special effect.

can anyone give me a hint or two on how to rip this level without the special effect.

many thanks this special effect is driving me crasy.